Spiders (Aranea)
Spiders are the most familiar of the arachnids and are the largest group with the posible exception of the mites.
The body of the spider is made up of two parts - The harder cephalothorax and the relatively softer abdomen. The front pair of legs are longer. They have no antennae but have a pair of palps at the front which could be mistaken for them. Male Spiders have clubbed palps which they use in courtship and mating. Most spiders have eight simple eyes though some have fewer. The eyes are of differing size and are arranged in patterns on the cephalothorax.
Spiders are predatory. Some spin elaborate webs using silk produced from glands within the spiders body. Others are hunting spiders that leap on passing prey. They possess a pair of poison fangs which they use to paralyse their prey before wrapping it in silk.
These spiders lie in wait for their prey amongst flowers leaves etc.
They rely on superb camouflage and will pounce on their prey as it comes into range.The front pair of legs are noticeably longer than the other three pairs. They have a sideways walk which gives this group its common name.
This family is superficially similar to the "true" crab spiders in the family Thomisidae.
However, studies have shown that these families are not as closely related as previously thought. Unlike thomisids, philodromids tend to have few true setae (hairs or spines) on their bodies. They also lack the congruent eye tubercles of some thomisids. The second legs are usually the longer of the four pairs of walking legs and in the genus Ebo this is quite extreme, with the second pair of legs in some species twice as long as the first pair.
The spiders in this group spin almost circular webs which are attached to tha available vegatation.
The orb comprises radial threads on which sticky spiral threads are placed. Waxy hairs on the spiders feet prevent the spider itself becoming trapped in its own web. Most spiders will retreat a short way from the web but in contact with a signal line that alerts the spider to the arrival of potential prey.
The tangle-web spiders (Theridiidae), also known as cobweb spiders and comb-footed spiders, are a large family (over 2200 species in over 100 genera) of three-dimensional space-web-builders found throughout the world.
Theridiid spiders are entelegyne (have a genital plate in the female) araneomorph ecribellate (use sticky capture silk instead of woolly silk) spiders that often build tangle space webs and have a comb of serrated bristles (setae) on the tarsus of the fourth leg.
The long-jawed orb weavers or long jawed spiders (family Tetragnathidae) are elongated spiders with long legs and chelicerae. The spiders are orb web weavers, weaving small orb webs with an open hub and few, wide-set radii and spirals. The webs have no signal line and no retreat. Some species are often found in long vegetation near water.
More info can be found on Wikipedia